Events
On This Day - September 21
| 1917 | K2 | One member of the crew accidentally fell overboard and was drowned. He was Sto 1 Reginald Tinniswood. |
| 1918 | L55 | Launched |
| 1932 | 1911 - 1932: Adamant | Sold |
| 1942 | Unruffled (P46) | At 0105 hours HMS Unruffled sinks the Italian auxiliary minesweeper N 10/Aquila with gunfire off the Tunisian coast 8 nautical miles bearing 040 from Mehedia. |
| 1943 | Unseen (P51) | HMS Unseen torpedoed and sank the German mine-layer Brandenburg and the German night fighter direction vessel Kreta. By firing a full salvo when the two target ships were overlapping, HMS Unseen achieved the remarkable result of sinking both vessels simultaneously, about 7 nautical miles northeast of Isola di Capraia, Italy. |
| 1943 | P52 | Fired torpedoes off Bastia harbour, Corsica, France and sank the German transport Nikolaus and the German tug Kraft. Dzik also claimed the sinking of a second transport and several German landing craft. |
